1. Field of the Invention
The present invention relates to parts for two-wheeled vehicles and, more particularly, to two-wheeled vehicle parts incorporating a functional element in a speedometer or the like.
2. Description of the Background Art
Recently, speedometers are sometimes attached to bicycles in order to readily know travel speed, travel distance or the like of the bicycles.
FIG. 9 is a plan view showing structure of such a speedometer; FIG. 10 is a sectional view taken along the line X--X of FIG. 9; and FIG. 11 is a rear view of the speedometer of FIG. 9.
The structure of the speedometer will now be described with reference to FIGS. 9-11.
A display portion 3 in which a liquid crystal display (LCD) is made through a lens 4 is formed in a central portion of a front surface of the speedometer. A mode switch 5 for switching various types of measuring modes and a start/stop switch 7 for switching the start and the stop of measurement are formed in a lower portion of the speedometer. Speedometer 1 comprises a lower cover 13 for covering a portion where such a functional element as a crystal oscillator 23 is attached to a base plate 21, and an upper cover 11 having display portion 3 attached thereto. In lower cover 13, a bracket groove 45 that is slidably engaged with a bracket (not shown) attached to component parts such as a handle or the like of a bicycle is formed. A battery cover 17 that is freely opened or closed for use in attachment of a battery 19 is formed in the center of lower cover 13. End surfaces of upper cover 11 and lower cover 13 correspond to each other over their entire circumferences. An O ring 39 attached to a groove formed in upper cover 11 allows an attachment of upper cover 11 and lower cover 13 by sealing. In this state, by fastening screws 41 set at four corners of lower cover 13, the inside of the speedometer is protected from being affected by water drops or the like from the outside by action of the O ring.
In the above-described conventional two-wheeled parts, O rings 39 must be attached on the entire circumference, and screws 41 must be attached to the external four corners, as also shown in FIG. 11. Thus, a complicated manufacture is inevitably required to process attachment portions of the O rings, and two-wheeled vehicle parts must be unnecessarily larger in order to obtain attachment portions for screws 41 at the four corners.